. . "From an economic standpoint, the preferred (co)polymers include polymers and copolymers of ethylene and propylene, such as polyethylene, polypropylene, copolymers of ethylene and propylene, ethylene/vinyl acetate copolymers, copolymers of ethylene and acrylic compounds, terpolymers based on olefin, methyl acrylate and ethyl acrylate or even mixtures of straight-chain and branched low density polyo" . . . .